This invention relates to a process for the preparation of refined hard sugarcane wax having improved qualities from press mud
Sugarcane wax (the hard variety) is a replacement of the commonly used carnauba wax. By nature sugarcane wax (the hard variety) is a type of microcrystalline wax having a high potential used in preparation of several important industrial products. Its potential use is wide in industry. The refined variety of the hard sugarcane wax having its potential use in: (a) Medicines, (b) in sweet meats and pastries, (c) in tinned food products, (d) in castings and recordings, (e) in carbon papers, (f) in preparation of carbonless carbon papers, (g) in electrical insulation of cables and wires, (h) in preparation of various types of paints, varnishes and polishes including shoe polishes, car polishes and floor polishes, (i) in preparation of coloured pencils, crayons, water and oil paints, (j) in cosmetics, (k) in preparation of emulsion paints for spraying. In fact, it has its most likely entries into all the branches of industries where carnauba wax is mostly used. In bulk also it can be produced many times more than any other plant waxes combined together. The raw material, press mud is a rejected waste material of sugarcane industries, that causes the unwanted problem of pollution to the surrounding supurbs of the sugar mills on accumulation. Also, the availability of the press mud is no problem at all throughout the year. While carnauba plant is a seasonal plant that produces extractable waxes only in marked period of a year.
(ii) The CHEMISTRY and TECHNOLOGY of WAXES by ALBIN H. WARTH Wax Research Consultant, Formerly Chemical Director The Crawn Cork and Seal Company Baltimore, Md.
REINHOLD PUBLISHING CORPORATION New York CHAPMAN and HALL LTD., LONDON.
The mode and the process of refining sugarcane wax (the hard variety) as mentioned above probably implies high acid values and saponification numbers to the presently available refined hard sugarcane wax of the world market.
The value of the wax increases with its colour and refining techniques. In the known process isolation of sugarcane wax from press mud (sugarcane press mud) is done commercially by use of solvents such as benzene, toluene, heptane and sometimes turpentine oils. The production of sugarcane wax is mainly been done only in one or two places in the world commercially. In India, Ravalgaon Sugar Industry prepares some amount of cane wax for its own use. The refining of the crude cane wax has been done by these industries by methods described in brief on the previous page.
The main object of the present invention is to develop a process for isolation and refining crude sugarcane-wax by using polar solvent such as carbon tetrachloride (CCl4) and activated charcoal. Another object of this invention is to provide a process which can produce hard wax having low acid values and low saponification number. Still another object of this invention is to produce simultaneously soft wax, pitch and starting material for agro manures as by-product.
The use of activated charcoal in refining crude sugarcane wax has not yet been included in industries producing sugarcane wax from press mud wastes. This is so because it is considered to be a mild agent for performing refining of sugarcane wax. Stronger refining agents such as sulphuric acid, nitric acid and chromic acids are presently being used for refining sugarcane wax in industry. Further refining of the industrial sugarcane wax is being done by the use of low pressure vacuum distillations. Probably, by the use of such methods (acid treatment) may be the cause of imparting higher acid values and higher saponification numbers to the presently available limited quantities of hard sugarcane wax of the world market.
Accordingly, the present invention provides a process for the preparation of refined hard sugarcane wax having improved qualities from press mud which comprises
(1) digesting press mud with a non polar solvent such as carbon tetrachloride (CCl4), benzene (C6H6) or toluene (C7H8) in presence of activated charcoal, where in the ratio of the non polar solvent:activated charcoal:press mud ranges from 3 liters to 1.50 liters:50 gm to 20 gm:1 kg to 500 gm (60 to 75:1:20 to 25);
(2) separating the residue by known methods;
(3) removing the solvent by conventional methods followed by treating the crude sugarcane wax obtained with hot isopropyl alcohol to get the wax in solution and pitch as residue;
(4) separating the said wax in solution by known methods and cooling to room temperture so as to get the said wax precipitated;
(5) washing thoroughly with water till the isopropyl alcohol is removed and drying to get the hard sugarcane wax;
(6) if desired recycling the isopropyl alcohol (I.P.A.) to step (3) and then treating the said sugarcane wax with hot water for further refining.
The present invention provides a better process than the existing commercial method of isolation and refining of sugarcane hard wax having low acid values and saponification numbers from press mud waste. In the process of the present invention carbon tetrachloride (CCl4) has been used as solvent for extraction of press mud in isolating sugarcane wax. This solvent has not yet been used industrially for extraction of sugarcane wax from press mud. In the extraction of press mud by the method of the present invention, carbon tetrachloride has been found as efficient as any other polar solvents used industrially for the purpose. Moreover, CCl4 have its advantages also. It is non-carcenogenic and non-imflamable. Activated charcoal is used for refining the crude cane wax. The product, sugarcane wax obtained by this process has a nominal acid value and saponification number. The colour of the hard wax obtained is light cream in colour, which is being highly preferred in the present world market. This is being made clear in the Table 1. The product by the process of the present invention is being compared with that of the commercial product present in the American market.
A reference can be made to page number 228 of THE CHEMISTRY AND TECHNOLOGY OF WAXES BY ALBIN h. WARTH.
This process of the present invention is a successfully developed method of acquiring high grade refined sugarcane wax (the hard variety) by using CCl4 for extraction of press mud and activated charcoal for refining the wax extracted. The use of mineral acids and distillation at reduced pressure employed in the hitherto known process for refining the crude wax and the hard wax obtained has been successfully avoided. For further refining, the wax obtained was treated and melted in hot water and then cooled to room temperature to recover the wax. This process removes any water soluble impurities if present, from the wax. This product prepared by the present invention has a nominal acid value and saponification number, and, in appearance, the wax is creamy-coloured lumps.
According to the present process, the air-dried press mud was digested with a nonpolar organic solvent, such as carbon tetrachloride (CCl4), benzene (C6H6) and toluene (C466) in the ratio of 2:3 to 2:5 at a temperature range of 80xc2x0 C. to 90xc2x0 C. (for CCl4 and benzene) and up to 110xc2x0 C. for tolouene. The digestion of the press mud has been done with any of these solvents for about 3 (three) to 7 (seven) hours at a stretch in presence of activated charcoal. The digested lot has been cooled to room temperature and filtered under subjection to vacuum filtration system by the use of an exhaust pump The residues on the filter pad washed three to four times (washings may be extended is necessary) to eight to ten times with clean small lot of fresh extracting aluquots, the washings added to the bulk of the filtrate in the collecting flask. The solvent recovered by distillation and the crude wax obtained transferred to a dried weighed empty beaker. Further removal of the solvent was performed by heating and removing the solvent at a temperature in the range of 80xc2x0 C. to 100xc2x0 C. For this a constant boiling water batch or a controlled heating mantle proves handy. The final removal of the solvent has been done in a vacuum desicator subjected to reduced pressure with a connected exhaust pump. The crude wax after being weighed was treated with hot isopropyl alcohol (I.P.A) at 1:3 to 1:6 ratio. All the waxes dissolved and a black compound remained adhered to the bottom of the beaker. This is the calcium-magnesium salts of waxy acids and resin acids. It is very sticky in nature. The hot solution of waxes was poured into a clean dried beaker and the interior of the first beaker washed several times with small lot (about 10 ml portion) I.P.A. for each washing and ringing, and decanted into the second beaker containing wax solution in I.P.A. The second beaker has been left to attain the room temperature so that the hard sugarcane wax separate out The hard wax has been retained on the filter pad on subjection to vacuum filtration by the use of an exhaust pump. The hard wax on the filter pad has been washed several times with small lot (about 10 to 50 ml portion) of fresh I.P.A. The hard wax on the filter pad has been subjected to air drying by letting air pass through the filter pad with the wax with the aid of the exhaust pump. The final drying has been done by heating the funnel with the wax at about 40xc2x0 C. to 45xc2x0 C. in an electric oven for about 30 minutes to 1 hour, and then subjected to exhaust in a vacuum desicator. Then the wax has been detached from the filter pad and dried further. The dried wax (physically powdery in character) has been melted and made into hard lumps of refined sugarcane wax (hard variety) cream-coloured in appearance. For further refining, the dried wax has been melted in clean hot water and the wax being recovered from the re-cooled water. This treatment removes and reduces any water soluble impurities if present in the hard sugarcane wax prepared.
In the execution of the experiments and extractions mentioned above previously, activated charcoal has been used for refining the waxes obtained.
The yield of wax obtained by the process concerned has been 5.00 to 5.50% hard wax and 4.00 to 4.50% soft wax.
Proper removal of the isopropyl alcohol (I.P.A.) has been found to be necessary because presence of I.P.A. in the hard wax portion (even in small amount) found to form colloidal layer when being treated with hot water, and this colloidal property remains as such even when the water wax part concerned has been brought down to the room temperature.